//1.原始图片

    UIImage * image = [UIImage imageNamed:@"1.jpg"];

    /****************core image******************/

    //a.图片

    CIImage * ciImage = [[CIImage alloc] initWithImage:image];

    //b.滤镜

    CIFilter * ciFilter = [CIFilter filterWithName:@"CIGaussianBlur"];

    NSLog(@"%@",[ciFilter attributes]);

    //设置滤镜的模糊程度,默认是10

    [ciFilter setValue:@() forKey:@"inputRadius"];

    //将图片放到滤镜中

    [ciFilter setValue:ciImage forKey:kCIInputImageKey];

    //输出图片

    CIImage * outImage = [ciFilter valueForKey:kCIOutputImageKey];

    //c.获取CGImage的句柄

    CIContext * context = [CIContext contextWithOptions:nil];

    CGImageRef outCGImage = [context createCGImage:outImage fromRect:[outImage extent]];

    UIImage * blurImage = [UIImage imageWithCGImage:outCGImage];

    CGImageRelease(outCGImage);

    /********************************************/

    //2.初始化imageView

    UIImageView * imageView = [[UIImageView alloc] initWithFrame:CGRectMake(, , , )];

    imageView.image = blurImage;

    [self.view addSubview:imageView];